Efficient Coupling of Reaction Pathways of Criegee Intermediates and Free Radicals in the Heterogeneous Ozonolysis of Alkenes

• DOI: 10.1021/acs.jpclett.0c01823
• Publication Date: 2020-07-26T20:46:46Z
• Authors: Meirong Zeng; Kevin R. Wilson
• Keywords: Alkene; Reactivity; Free-radical reaction; Reaction intermediate

In the gas phase, ozonolysis of olefins is known to be a significant source free radicals. However, for heterogeneous and condensed phase ozone reactions, importance reaction pathways that couple Criegee intermediates (CI) with hydroxyl (OH), alkoxy, peroxy radicals remains uncertain. Here we report experimental evidence substantial radical oxidation during O3 cis-9-tricosene (Tri) aerosol. A kinetic model three coupled submechanisms include O3, CI, reactions used explain how observed Tri reactivity its product distributions depend upon [O3], [OH], presence CI scavengers. During multiphase ozonolysis, predicts only ∼30% alkene actually consumed by while remaining ∼70% cycle through involving CI. These results reveal which has been previously difficult isolate due complex coupling OH pathways.